- Museum number
MOVEMENT AND DIAL OF A LEVER WATCH WITH INDEPENDENT CENTRE-SECONDS.
Watch with independent centre-seconds train; movement,dial and dust-cap.
Full-plate, fusee, Harrison's maintaining-power, hollow 2nd-pinion, ratchet-tooth lever-escapement, plain gold 3-arm balance, over-sprung.
The independent-seconds train is driven by the 3rd-wheel to a hollow pinion which is of the same count and diameter as the 4th-pinion, planted centrally, in the frame, and riveted to a miniature barrel. This, in turn, houses a slipping spring the eye of which is hooked to an arbor running through the hollow pinion and having the independent 4th-wheel mounted on it. The train ends in the usual way. When the stop is operated the slipping spring is continually being wound up by the going train. When the stop is released the train is wound between each release of the fly. The stop acts on the fly.
Dial; enamel, 3-piece, white with black I-XII numerals, sunk centre, sunk subsidiary seconds dial.
Hands; gold moon, hour hand broken, blued steel centre-seconds and sub-seconds hands.
- Production date
Diameter: 45.60 millimetres (dial)
Diameter: 42.50 millimetres (dust-cap)
Thickness: 12.70 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Charles Read, Junior
Whitehaven, c. 1865
Movement of a single-barrel ratchet tooth lever watch with independent centre-seconds.
Signature: 'CHAS READ JUNR PATENT' on the dial, 'Patent Independent Seconds No 12' on the back plate and 'Sutton WHITEHAVEN' on the barrel bridge.(1)
Dial & Hands: Flat dial with a sunk centre and a sunk subsidiary seconds dial. The dial is chipped around the seconds dial. The number '12' fired into the counter-enamel. The gold moon-pattern minute hand is not original and the gold hour hand is broken and partly missing. Blued-steel centre-seconds and subsidiary seconds hands, (the latter also not original).
Dial-plate: None intended, the dial is pinned directly to the front plate.
Dust-cap: Stamped 'JAK' and scratched '8' on the inside. The dust-cap is pierced for the winding arbor, the hand-set arbor, the balance cock table and also the balance cock screw.
Ebauche Marks: WF 16 0
Frame: A full plate layout, the back plate supported by four turned pillars. The balance cock engraved all over with foliate scrolls and stamped 'J.R' on the underside of the foot. A separate pipe is fitted over the winding square. An escapement protection pin is fitted to the inside of the front plate.
Fusee, Barrel and Mainspring:
Fusee: four-turn fusee with Harrison's maintaining power with a steel maintaining ratchet wheel.
Barrel: internal diameter 17.6 mm, height 2.8 mm.
Mainspring: height 2.6 mm, thickness 0.25 mm.
Barrel Arbor: diameter 5.3 mm, not snailed.
Train: Polished brass wheels, the second, third and fourth wheels with five crossings. There are in effect two fourth wheels both driven by the third wheel. One is planted to carry the drive from the third wheel to the escape wheel and the other, the centre-seconds wheel, is planted at the centre of the movement and carries the centre-seconds hand.
Jewelling: Jewelled bearings for the fourth wheel in both trains, also for the escape wheel and balance. There are ruby endstones for the balance. All but the fourth jewel in the front plate are in screwed settings.
Escapement: An acute-angle layout ratchet tooth lever escapement with short lever, single roller and round impulse pin. The enclosed pallet stones have convex impulse and locking faces. The polished brass escape wheel has three crossings.
An equal impulse escapement.
No. of teeth embraced 32.
Balance & Spring: A rounded-rim, gold, three-arm balance, diameter 17.6 mm, thickness 0.6 mm. A blued-steel flat spiral spring with 93 turns pinned to a polished steel stud screwed to the back plate.
Means of Regulation: An index on the balance cock registers against a silver scale screwed to the back plate, with 'SLOW' and 'FAST' engraved on the back plate at the ends of the scale.
Train Counts and Beat Rate:
Great wheel 74 (fusee)
Second wheel 64 pinion 10
Third wheel 60 pinion 8
Fourth wheel 60 pinion 8
Escape wheel 15 pinion 7
Beat Rate: 15,428.571
Fourth Wheel 60 pinion 8 (rotates once a minute)
Fifth wheel 60 pinion 10 (rotates once 10 seconds)
Flirt pinion 6 (rotates once in a second)
The third wheel of the going train drives the centre-seconds fourth pinion which is connected through a slipping mainspring in a diminutive barrel to a fifth wheel and flirt. Thus the independent train can be started and stopped without stopping the watch. The stop acts on the flirt.
Motion work: Intermediate 36
cannon wheel 36
minute wheel 36, minute pinion 6
hour wheel 72
The second wheel arbor is hollow and accommodates a friction-tight central pin with a hand setting square at the rear and the intermediate wheel on the front which then meshes with the minute wheel to drive the motion work. A brass spring attached to a stud on the front plate acts on the face of the minute wheel to prevent backlash.
Winding System: Key wound.
Movement: diameter 45.6 mm, height 13.0 mm, pillar height 3.0 mm.
Provenance: Formerly in the Ilbert Collection. Ilbert purchased this in the Calendonian market 23/8/1932.
(1) Probably Robert Sutton (1858-1879) of Whitehaven.
Although there appears to be no record of a patent registered to Charles Read junior, the mechanism found in this watch is very similar to that described in patent no. 57 of 8 January 1862, in the name of William Bradshaw the younger.
- Not on display
Latest: 4 (2017) rust on centre secs boss
2 (Dec 1994)
- Acquisition date
- Acquisition notes
- Following the successful acquisition of the celebrated Ilbert collection of clocks (1958,1006 collection), prints and other related materials made possible by the generous donation of funds by Gilbert Edgar CBE Ilbert's watches were then acquired using funds provided by Gilbert Edgar, public donations and government funds.
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.1152 (Ilbert Collection)
Previous owner/ex-collection number: M181 (Ilbert Ledger)